1. Field of the Invention
The present invention relates to an electrophotographic photoreceptor.
2. Description of the Prior Art
Recently, there have been various proposals for developing an electrophotographic photoreceptor having an amorphous silicon based photosensitive layer formed on a support therein. Electrophotographic photoreceptors having an amorphous silicon based photosensitive layer have a good electrophotographic characteristics in mechanical strength, panchromatic property, and sensitivity for lights having a relatively long wavelength in general.
One of the proposals for further improvement of electrophotographic photreceptors includes an electrophotographic photoreceptor of a function separation type in which the photosensitive layer is functionally divided into a charge generating layer and a charge transporting layer, and other proposals include an electrophotographic photoreceptor in which the photosensitive layer includes boron, and the like (for example, Japanese Patent Unexamined Publication No. 60-112048).
In these more conventional electrophotographic photoreceptors of the type having a surface layer and an amorphous silicon based photosensitive layer, when boron is added into the amorphous silicon based photosensitive layer, the electrophotographic characteristics of the photoreceptor are often not satisfactory, depending in part on the extent of concentration of boron in the photosensitive layer and the material composition of the surface layer provided on the photosensitive layer. More particularly, when the surface layer includes a nitrified amorphous silicon film, image flow or image fading in copied images obtained from the photoreceptors often occurs.